From 2456242530a21cfee82646ebeeda65d3f74faa4c Mon Sep 17 00:00:00 2001
From: Yan Zheng <zheng.yan@oracle.com>
Date: Thu, 12 Feb 2009 14:14:53 -0500
Subject: [PATCH] Btrfs: hold trans_mutex when using btrfs_record_root_in_trans

btrfs_record_root_in_trans needs the trans_mutex held to make sure two
callers don't race to setup the root in a given transaction.  This adds
it to all the places that were missing it.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
---
 fs/btrfs/extent-tree.c | 2 ++
 fs/btrfs/transaction.c | 2 ++
 fs/btrfs/tree-log.c    | 2 ++
 3 files changed, 6 insertions(+)

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index cd86bffbdc9f..0a5d796c9f7e 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -5658,7 +5658,9 @@ static noinline int relocate_one_extent(struct btrfs_root *extent_root,
 			prev_block = block_start;
 		}
 
+		mutex_lock(&extent_root->fs_info->trans_mutex);
 		btrfs_record_root_in_trans(found_root);
+		mutex_unlock(&extent_root->fs_info->trans_mutex);
 		if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
 			/*
 			 * try to update data extent references while
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 919172de5c9a..4112d53d4f4d 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -688,7 +688,9 @@ static noinline int drop_dirty_roots(struct btrfs_root *tree_root,
 		num_bytes -= btrfs_root_used(&dirty->root->root_item);
 		bytes_used = btrfs_root_used(&root->root_item);
 		if (num_bytes) {
+			mutex_lock(&root->fs_info->trans_mutex);
 			btrfs_record_root_in_trans(root);
+			mutex_unlock(&root->fs_info->trans_mutex);
 			btrfs_set_root_used(&root->root_item,
 					    bytes_used - num_bytes);
 		}
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 20794290256b..9c462fbd60fa 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -2832,7 +2832,9 @@ int btrfs_recover_log_trees(struct btrfs_root *log_root_tree)
 		BUG_ON(!wc.replay_dest);
 
 		wc.replay_dest->log_root = log;
+		mutex_lock(&fs_info->trans_mutex);
 		btrfs_record_root_in_trans(wc.replay_dest);
+		mutex_unlock(&fs_info->trans_mutex);
 		ret = walk_log_tree(trans, log, &wc);
 		BUG_ON(ret);
 
-- 
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